The present invention relates to support assemblies for use in mine workings and, more particularly, to improved forms of floor structures for such assemblies.
Support assemblies of various constructions are employed in mine workings. Usually, such assemblies are displaceable to follow up the winning progress and their floor-sills often utilize skids for sliding over the floor of the working. To enable the assembly to cope with irregularities in the floor surface, the skids are conventionally spaced apart laterally of the assembly and interconnected in a flexible manner permitting relative displacement between the skids. Where the floor is especially soft, it is known to increase the floor-engaging area of the skids with the aid of a front-attachment skid extending the whole width of the assembly and fitted to the main skids with bolts or spindles. An arrangement of this type is described in German Pat. No. 2453257. This known arrangement suffers from a number of disadvantages. The front skid can only be used with one type of floor structure, i.e. with two floor skids spaced apart by a certain distance, and it cannot be used with other forms of floor structure, e.g., with a single individual floor skid. When the front skid is affixed to the spaced-apart floor skids, it bridges the gap therebetween and thus negates the capacity of the floor structure to adapt to floor irregularity by relative displacement between the floor skids. The front skid also takes up considerable space and generally obstructs means, usually a beam, connecting the assembly to a conveyor. This latter disadvantage is especially a problem with thin mineral seams where the connecting means or beam should be as close to the floor as possible.
A general objection of the present invention is to provide an improved adaptable floor sill structure for a support assembly.